Method for reducing loudspeaker phase distortion

Abstract

A method for reducing loudspeaker magnitude and/or phase distortion, in which one or more filters pertaining to one or more drive units is automatically generated or modified based on the response of each specific drive unit. The drive unit response may be determined by electromechanical modelling of the drive unit. Drive unit models may be enhanced by electromechanical and/or acoustic measurement such that the resulting filter becomes specific to each specific drive unit.

1 . A method for reducing loudspeaker magnitude and/or phase distortion, in which one or more filters pertaining to one or more drive units is automatically generated or modified based on the response of each specific drive unit and in which improved drive unit model or measurement data is stored remotely and sent over the internet to update the filter or filters for a specific drive unit. 
     
     
         2 . The method of  claim 1 , in which the drive unit response is determined by modelling the drive unit. 
     
     
         3 . The method of  claim 1 , in which the drive unit response is determined by electro-mechanical modelling of the drive unit. 
     
     
         4 . The method of  claim 3 , in which the electro-mechanical modelling is enhanced by electro-mechanical measurement of a specific drive unit such that the resulting filter becomes specific to that drive unit. 
     
     
         5 . The method of  claim 3  in which the electro-mechanical modelling of the drive unit is defined using any one or more of the parameters f s , Q TS , R E , L c  or L VC . 
     
     
         6 . The method of  claim 2 , in which the drive unit response is determined by acoustic modelling of the drive unit. 
     
     
         7 . The method of  claim 2 , in which the modelling incorporates any electronic passive filtering in front of the drive unit. 
     
     
         8 . The method of  claim 3 , in which the electro-mechanical modelling is enhanced by electro-mechanical measurement of the passive filtering in front of each drive unit. 
     
     
         9 . The method of  claim 2 , in which the modelling is enhanced by the use of acoustic measurements of a specific drive unit. 
     
     
         10 . The method of  claim 2 , in which the filter is automatically generated or modified using a software tool or system based on the above modelling and is implemented using a digital filter, such as a FIR filter. 
     
     
         11 . The method of  claim 1 , in which the filter incorporates a band limiting filter, such as a crossover filter, such that the resulting filter exhibits minimal or zero magnitude and/or phase distortion when combined with the drive unit response. 
     
     
         12 . The method of  claim 1 , in which the filter incorporates an equalisation filter such that the resulting filter exhibits minimal or zero magnitude and/or phase distortion when combined with the drive unit response. 
     
     
         13 . The method of  claim 1 , in which the filter is performed prior to a passive crossover such that the filter, when combined with the passive crossover and the drive unit response reduces the magnitude and/or phase distortion of the overall system. 
     
     
         14 . The method of  claim 1 , in which the filter is performed prior to an active crossover such that the filter, when combined with the passive crossover and the drive unit response reduces the magnitude and/or phase distortion of the overall system. 
     
     
         15 . The method of  claim 2 , in which the drive unit model is derived from an electrical impedance measurement. 
     
     
         16 . The method of  claim 2 , in which the drive unit model is enhanced by a sound pressure level measurement. 
     
     
         17 . The method of  claim 1 , in which the filter operates such that the signal sent to each drive unit is delayed such that the instantaneous sound from each of the multiple drive units arrives coincidentally at the listening position. 
     
     
         18 - 20 . (canceled) 
     
     
         21 . The method of  claim 2  in which, if the drive unit is replaced, then the filter is updated to use the modelling data for the replacement drive unit. 
     
     
         22 . (canceled) 
     
     
         23 . The method of  claim 1  in which the response of a drive unit for the loudspeaker are measured whilst in operation and the filter is regularly or continuously updated, for example in real-time or when the system is not playing, to take into account electro-mechanical variations, for example associated with variations in operating temperature. 
     
     
         24 . The method of  claim 1  in which volume controls of the loudspeaker are implemented in the digital domain after the filter such that filter precision is maximised. 
     
     
         25 . A loudspeaker including one or more filters each pertaining to one or more drive units, in which the filter is automatically generated or modified based on the response of each specific drive unit and in which improved drive unit model or measurement data is stored remotely and sent over the internet to update the filter or filters for a specific drive unit. 
     
     
         26 . (canceled) 
     
     
         27 . A media output device, such as a smartphone, tablet, home computer, games console, home entertainment system, automotive entertainment system, or headphones, comprising at least one loudspeaker including one or more filters each pertaining to one or more drive units, in which the filter is automatically generated or modified based on the response of each specific drive unit and in which improved drive unit model or measurement data is stored remotely and sent over the internet to update the filter or filters for a specific drive unit. 
     
     
         28 . (canceled) 
     
     
         29 . A software-implemented tool that enables a loudspeaker to be designed, the loudspeaker including one or more filters each pertaining to one or more drive units, in which the tool or system enables the filter to be automatically generated or modified based on the response of each specific drive unit and in which improved drive unit model or measurement data is stored remotely and sent over the internet to update the filter or filters for a specific drive unit. 
     
     
         30 . (canceled) 
     
     
         31 . A media streaming platform or system which streams media, such as music and/or video, to networked media output devices, such as smartphones, tablets, home computers, games consoles, home entertainment systems, automotive entertainment systems, and headphones, in which the platform enables the acoustic performance of the loudspeakers in specific output devices to be improved by minimizing their phase distortion, by enabling one or more filters each pertaining to one or more drive units to be automatically generated or modified based on the response of each specific drive unit, or for those filters to be used and in which improved drive unit model or measurement data is stored remotely and sent over the internet to update the filter or filters for a specific drive unit. 
     
     
         32 - 42 . (canceled)